Пошаговое объяснение:
Дано: 16 1/2 : 11 + 9 1/6 = ?
16 1/2 : 11 = 33/2 : 11 = 3/2 = 1 1/2
1 1/2 + 9 1/6 = 9/6 + 55/6 = 64/6 = 10 2/3 - ответ.
<span>х(х+4)=12</span>
<span>х*х+4х=12</span>
<span>2х+4х=12</span>
<span>6х=12</span>
<span>х=12:6</span>
x=2